New ACO instruments were installed during the ACO-3 cruise on 2014/11/01.
Click here for ACO-3 videos.

Click below for real-time data

The University of Hawaii's ALOHA Cabled Observatory is located 100 km north of the island of Oahu, Hawaii (22 45'N, 158W) in the North Pacific Ocean. It provides real-time oceanographic observations from a depth of about 4,800 m via a submarine fiber optic cable that comes ashore at Makaha on Oahu. In addition to ocean sounds, continuous observations of temperature, salinity, and ocean currents are obtained and shared with the oceanographic community and the general public.

Bruce Howe (PI) talks about the ACO on ThinkTech Hawaii

8.2 magnitude Chile earthquake recorded by the ACO

April 2nd, 2014 Chile earthquake, magnitude 8.2, detected by the ACO broadband hydrophone. The x axis is UTC time in hh:mm:ss. The red curve shows the energy band-passed between 0.01-0.15 Hz and the blue curve is the data from 3.5 -10 Hz. The large high frequency signal is the T-phase arrival from the earthquake source. (graphic by Fred Duennebier)

2011-2012 and 2013 cold water events observed by ACO

This graphic shows potential temperature and salinity from the ALOHA Cabled Observatory, along with the values from near-bottom CTD measurements about 1.8 km away during HOT cruises, the most recent being HOT-254 that returned on September 14, 2013.

This shows that a very dramatic cold event occurred over the last three weeks, with a peak-to-trough change of 0.02 C. It is typically thought that day-to-day changes in the abyss (away from deep convection) are only of order 0.001 C.

We can see a drawn out warming/recovery during the interval between the two cold overflow events. This is consistent with a relatively slower turbulent flux of heat downward in the interim between Kauai Deep ventilation events.

The CTD measurements are taken over only a few minutes. The ACO values are daily averages to average out internal tides (and after removing observatory signatures.)

The ACO Microcat salinity had a mean offset prior to February of this year of ~0.02, with a drift of about 0.01 over the prior months. There is a clear jump in calibration earlier this year, but we are not sure at this point whether the rate of drift has changed from before.

Primera video on ACO's use of Blu-Ray robot

Bruce Howe (PI), Roger Lukas (Co-PI), and Brian Chee talking about the Primera Blu-Ray burner/printer robot that's currently in use to archive ACO Hydrophone and engineering data to an archival media. The Blu-Ray burner/printer was donated by Primera Corporation.

Whales migrating to Alaska for the summer

Humpback whales are now leaving their winter home near Hawaii and
heading back north. Rather than "singing", they make simple repeated
calls to navigate and let others know where they are, The plot shows
sound power by color, with the reddest colors being the loudest. The
vertical scale is frequency in Hertz, and the horizontal time scale is
in seconds. Each loud call (clearest between 40-100 Hz) is followed
about 3 seconds later by a similar weaker signal, likely a reflection
off the ocean surface, then another signal about 6.5 sec after the
first, likely reflected off the ocean floor, ocean surface, and then
back down to the hydrophone at the ocean floor.

The 8.6 magnitude Sumatra earthquake recorded by the ACO

A magnitude 8.6 earthquake struck off the coast of the Indonesian island of Sumatra on April 11, 2012. The event was recorded by the ACO hydrophone as shown on the left.

Listen to our new Shoutcast server with embedded web player to listen to whales near the ACO.
Embedded web player tested with IE9, Firefox, Chrome, and Opera. 64 listeners maximum. Click *here* to listen to the hydrophone in
real-time.

The ACO hydrophone detected Fin whales on November 21, 2011.
It is expected that more whales will be heard near the ACO site
in the coming months. Click *here* to listen to the hydrophone in
real-time and maybe you can hear a whale passing by (Real Player required PC / Mac).

The ACO video camera was able to record the visits of two
deep sea creatures. Colleagues in the Biological Oceanography
division of SOEST are looking towards using videos similar to
these to help understand the behavior of deep water shrimp and
sea cucumbers.

5 km beneath the surface of the ocean, the Aloha Cabled Observatory brings an infrequently observed and little understood habitat into light. Through cables and oceanographic instruments, scientists are able to look at the seafloor and in a way they rarely can: instantly and for years to come.

Connecting Station ALOHA to scientists on Oahu is a retired AT&T telephone cable. The observatory has the capacity to listen to ocean through hydrophones. The temperature and salinity in the water are measured. Through acoustic sensing, the current profiles above the seafloor are being plotted. This data is sent back to Oahu at the speed of light into the hands of those who analyze it to discover patterns of ocean circulation, ocean-atmosphere interactions and climate change.

The ALOHA Cabled Observatory (ACO) is a system of hardware and software that extends electric power and the Internet offshore, supporting sustained real-time observations in the deep ocean. The ACO is connected to Oahu, Hawaii by the HAW-4 telecommunications cable transferred to the project by AT&T in 2007.